﻿/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <assert.h>
#include <limits.h>
#include <stdlib.h>

#if defined(__MINGW64_VERSION_MAJOR)
 /* MemoryBarrier expands to __mm_mfence in some cases (x86+sse2), which may
  * require this header in some versions of mingw64. */
#include <intrin.h>
#endif

#include "uv.h"
#include "internal.h"

static void uv__once_inner(uv_once_t* guard, void (*callback)(void)) {
    DWORD result;
    HANDLE existing_event, created_event;

    created_event = CreateEvent(NULL, 1, 0, NULL);
    if (created_event == 0) {
        /* Could fail in a low-memory situation? */
        uv_fatal_error(GetLastError(), "CreateEvent");
    }

    existing_event = InterlockedCompareExchangePointer(&guard->event,
                                                       created_event,
                                                       NULL);

    if (existing_event == NULL) {
        /* We won the race */
        callback();

        result = SetEvent(created_event);
        assert(result);
        guard->ran = 1;

    } else {
        /* We lost the race. Destroy the event we created and wait for the existing
         * one to become signaled. */
        CloseHandle(created_event);
        result = WaitForSingleObject(existing_event, INFINITE);
        assert(result == WAIT_OBJECT_0);
    }
}


void uv_once(uv_once_t* guard, void (*callback)(void)) {
    /* Fast case - avoid WaitForSingleObject. */
    if (guard->ran) {
        return;
    }

    uv__once_inner(guard, callback);
}


/* Verify that uv_thread_t can be stored in a TLS slot. */
STATIC_ASSERT(sizeof(uv_thread_t) <= sizeof(void*));

static uv_key_t uv__current_thread_key;
static uv_once_t uv__current_thread_init_guard = UV_ONCE_INIT;


static void uv__init_current_thread_key(void) {
    if (uv_key_create(&uv__current_thread_key))
        abort();
}


struct thread_ctx
{
    void (*entry)(void* arg);
    void* arg;
    uv_thread_t self;
};


static UINT __stdcall uv__thread_start(void* arg) {
    struct thread_ctx* ctx_p;
    struct thread_ctx ctx;

    ctx_p = arg;
    ctx = *ctx_p;
    uv__free(ctx_p);

    uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
    uv_key_set(&uv__current_thread_key, ctx.self);

    ctx.entry(ctx.arg);

    return 0;
}


int uv_thread_create(uv_thread_t* tid, void (*entry)(void* arg), void* arg) {
    uv_thread_options_t params;
    params.flags = UV_THREAD_NO_FLAGS;
    return uv_thread_create_ex(tid, &params, entry, arg);
}

int uv_thread_create_ex(uv_thread_t* tid,
                        const uv_thread_options_t* params,
                        void (*entry)(void* arg),
                        void* arg) {
    struct thread_ctx* ctx;
    int err;
    HANDLE thread;
    SYSTEM_INFO sysinfo;
    size_t stack_size;
    size_t pagesize;

    stack_size =
        params->flags & UV_THREAD_HAS_STACK_SIZE ? params->stack_size : 0;

    if (stack_size != 0) {
        GetNativeSystemInfo(&sysinfo);
        pagesize = (size_t)sysinfo.dwPageSize;
        /* Round up to the nearest page boundary. */
        stack_size = (stack_size + pagesize - 1) & ~(pagesize - 1);

        if ((unsigned)stack_size != stack_size)
            return UV_EINVAL;
    }

    ctx = uv__malloc(sizeof(*ctx));
    if (ctx == NULL)
        return UV_ENOMEM;

    ctx->entry = entry;
    ctx->arg = arg;

    /* Create the thread in suspended state so we have a chance to pass
     * its own creation handle to it */
    thread = (HANDLE)_beginthreadex(NULL,
                                    (unsigned)stack_size,
                                    uv__thread_start,
                                    ctx,
                                    CREATE_SUSPENDED,
                                    NULL);
    if (thread == NULL) {
        err = errno;
        uv__free(ctx);
    } else {
        err = 0;
        *tid = thread;
        ctx->self = thread;
        ResumeThread(thread);
    }

    switch (err) {
    case 0:
    return 0;
    case EACCES:
    return UV_EACCES;
    case EAGAIN:
    return UV_EAGAIN;
    case EINVAL:
    return UV_EINVAL;
    }

    return UV_EIO;
}


uv_thread_t uv_thread_self(void) {
    uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
    uv_thread_t key = uv_key_get(&uv__current_thread_key);
    if (key == NULL) {
        /* If the thread wasn't started by uv_thread_create (such as the main
         * thread), we assign an id to it now. */
        if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
                             GetCurrentProcess(), &key, 0,
                             FALSE, DUPLICATE_SAME_ACCESS)) {
            uv_fatal_error(GetLastError(), "DuplicateHandle");
        }
        uv_key_set(&uv__current_thread_key, key);
    }
    return key;
}


int uv_thread_join(uv_thread_t* tid) {
    if (WaitForSingleObject(*tid, INFINITE))
        return uv_translate_sys_error(GetLastError());
    else {
        CloseHandle(*tid);
        *tid = 0;
        MemoryBarrier();  /* For feature parity with pthread_join(). */
        return 0;
    }
}


int uv_thread_equal(const uv_thread_t* t1, const uv_thread_t* t2) {
    return *t1 == *t2;
}


int uv_mutex_init(uv_mutex_t* mutex) {
    InitializeCriticalSection(mutex);
    return 0;
}


int uv_mutex_init_recursive(uv_mutex_t* mutex) {
    return uv_mutex_init(mutex);
}


void uv_mutex_destroy(uv_mutex_t* mutex) {
    DeleteCriticalSection(mutex);
}


void uv_mutex_lock(uv_mutex_t* mutex) {
    EnterCriticalSection(mutex);
}


int uv_mutex_trylock(uv_mutex_t* mutex) {
    if (TryEnterCriticalSection(mutex))
        return 0;
    else
        return UV_EBUSY;
}


void uv_mutex_unlock(uv_mutex_t* mutex) {
    LeaveCriticalSection(mutex);
}


int uv_rwlock_init(uv_rwlock_t* rwlock) {
    /* Initialize the semaphore that acts as the write lock. */
    HANDLE handle = CreateSemaphoreW(NULL, 1, 1, NULL);
    if (handle == NULL)
        return uv_translate_sys_error(GetLastError());
    rwlock->state_.write_semaphore_ = handle;

    /* Initialize the critical section protecting the reader count. */
    InitializeCriticalSection(&rwlock->state_.num_readers_lock_);

    /* Initialize the reader count. */
    rwlock->state_.num_readers_ = 0;

    return 0;
}


void uv_rwlock_destroy(uv_rwlock_t* rwlock) {
    DeleteCriticalSection(&rwlock->state_.num_readers_lock_);
    CloseHandle(rwlock->state_.write_semaphore_);
}


void uv_rwlock_rdlock(uv_rwlock_t* rwlock) {
    /* Acquire the lock that protects the reader count. */
    EnterCriticalSection(&rwlock->state_.num_readers_lock_);

    /* Increase the reader count, and lock for write if this is the first
     * reader.
     */
    if (++rwlock->state_.num_readers_ == 1) {
        DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, INFINITE);
        if (r != WAIT_OBJECT_0)
            uv_fatal_error(GetLastError(), "WaitForSingleObject");
    }

    /* Release the lock that protects the reader count. */
    LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
}


int uv_rwlock_tryrdlock(uv_rwlock_t* rwlock) {
    int err;

    if (!TryEnterCriticalSection(&rwlock->state_.num_readers_lock_))
        return UV_EBUSY;

    err = 0;

    if (rwlock->state_.num_readers_ == 0) {
        /* Currently there are no other readers, which means that the write lock
         * needs to be acquired.
         */
        DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, 0);
        if (r == WAIT_OBJECT_0)
            rwlock->state_.num_readers_++;
        else if (r == WAIT_TIMEOUT)
            err = UV_EBUSY;
        else if (r == WAIT_FAILED)
            uv_fatal_error(GetLastError(), "WaitForSingleObject");

    } else {
        /* The write lock has already been acquired because there are other
         * active readers.
         */
        rwlock->state_.num_readers_++;
    }

    LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
    return err;
}


void uv_rwlock_rdunlock(uv_rwlock_t* rwlock) {
    EnterCriticalSection(&rwlock->state_.num_readers_lock_);

    if (--rwlock->state_.num_readers_ == 0) {
        if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
            uv_fatal_error(GetLastError(), "ReleaseSemaphore");
    }

    LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
}


void uv_rwlock_wrlock(uv_rwlock_t* rwlock) {
    DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, INFINITE);
    if (r != WAIT_OBJECT_0)
        uv_fatal_error(GetLastError(), "WaitForSingleObject");
}


int uv_rwlock_trywrlock(uv_rwlock_t* rwlock) {
    DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, 0);
    if (r == WAIT_OBJECT_0)
        return 0;
    else if (r == WAIT_TIMEOUT)
        return UV_EBUSY;
    else
        uv_fatal_error(GetLastError(), "WaitForSingleObject");
}


void uv_rwlock_wrunlock(uv_rwlock_t* rwlock) {
    if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
        uv_fatal_error(GetLastError(), "ReleaseSemaphore");
}


int uv_sem_init(uv_sem_t* sem, unsigned int value) {
    *sem = CreateSemaphore(NULL, value, INT_MAX, NULL);
    if (*sem == NULL)
        return uv_translate_sys_error(GetLastError());
    else
        return 0;
}


void uv_sem_destroy(uv_sem_t* sem) {
    if (!CloseHandle(*sem))
        abort();
}


void uv_sem_post(uv_sem_t* sem) {
    if (!ReleaseSemaphore(*sem, 1, NULL))
        abort();
}


void uv_sem_wait(uv_sem_t* sem) {
    if (WaitForSingleObject(*sem, INFINITE) != WAIT_OBJECT_0)
        abort();
}


int uv_sem_trywait(uv_sem_t* sem) {
    DWORD r = WaitForSingleObject(*sem, 0);

    if (r == WAIT_OBJECT_0)
        return 0;

    if (r == WAIT_TIMEOUT)
        return UV_EAGAIN;

    abort();
    return -1; /* Satisfy the compiler. */
}


int uv_cond_init(uv_cond_t* cond) {
    InitializeConditionVariable(&cond->cond_var);
    return 0;
}


void uv_cond_destroy(uv_cond_t* cond) {
    /* nothing to do */
    (void)&cond;
}


void uv_cond_signal(uv_cond_t* cond) {
    WakeConditionVariable(&cond->cond_var);
}


void uv_cond_broadcast(uv_cond_t* cond) {
    WakeAllConditionVariable(&cond->cond_var);
}


void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
    if (!SleepConditionVariableCS(&cond->cond_var, mutex, INFINITE))
        abort();
}

int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
    if (SleepConditionVariableCS(&cond->cond_var, mutex, (DWORD)(timeout / 1e6)))
        return 0;
    if (GetLastError() != ERROR_TIMEOUT)
        abort();
    return UV_ETIMEDOUT;
}


int uv_barrier_init(uv_barrier_t* barrier, unsigned int count) {
    int err;

    barrier->n = count;
    barrier->count = 0;

    err = uv_mutex_init(&barrier->mutex);
    if (err)
        return err;

    err = uv_sem_init(&barrier->turnstile1, 0);
    if (err)
        goto error2;

    err = uv_sem_init(&barrier->turnstile2, 1);
    if (err)
        goto error;

    return 0;

error:
    uv_sem_destroy(&barrier->turnstile1);
error2:
    uv_mutex_destroy(&barrier->mutex);
    return err;

}


void uv_barrier_destroy(uv_barrier_t* barrier) {
    uv_sem_destroy(&barrier->turnstile2);
    uv_sem_destroy(&barrier->turnstile1);
    uv_mutex_destroy(&barrier->mutex);
}


int uv_barrier_wait(uv_barrier_t* barrier) {
    int serial_thread;

    uv_mutex_lock(&barrier->mutex);
    if (++barrier->count == barrier->n) {
        uv_sem_wait(&barrier->turnstile2);
        uv_sem_post(&barrier->turnstile1);
    }
    uv_mutex_unlock(&barrier->mutex);

    uv_sem_wait(&barrier->turnstile1);
    uv_sem_post(&barrier->turnstile1);

    uv_mutex_lock(&barrier->mutex);
    serial_thread = (--barrier->count == 0);
    if (serial_thread) {
        uv_sem_wait(&barrier->turnstile1);
        uv_sem_post(&barrier->turnstile2);
    }
    uv_mutex_unlock(&barrier->mutex);

    uv_sem_wait(&barrier->turnstile2);
    uv_sem_post(&barrier->turnstile2);
    return serial_thread;
}


int uv_key_create(uv_key_t* key) {
    key->tls_index = TlsAlloc();
    if (key->tls_index == TLS_OUT_OF_INDEXES)
        return UV_ENOMEM;
    return 0;
}


void uv_key_delete(uv_key_t* key) {
    if (TlsFree(key->tls_index) == FALSE)
        abort();
    key->tls_index = TLS_OUT_OF_INDEXES;
}


void* uv_key_get(uv_key_t* key) {
    void* value;

    value = TlsGetValue(key->tls_index);
    if (value == NULL)
        if (GetLastError() != ERROR_SUCCESS)
            abort();

    return value;
}


void uv_key_set(uv_key_t* key, void* value) {
    if (TlsSetValue(key->tls_index, value) == FALSE)
        abort();
}
static int s_global_send_size = 0;
static int s_global_recv_size = 0;

void uv_set_send_buff_size(int i) {
    s_global_send_size = i;
}

void uv_set_recv_buff_size(int i) {
    s_global_recv_size = i;
}

int uv_get_send_buff_size() {
    return s_global_send_size;
}

int uv_get_recv_buff_size() {
    return s_global_recv_size;
}
